Nelly Alleged Rape Case Evidence Released

All the evidence gathered in Nelly's alleged rape case has been released ... including surveillance videos and photos from the night of his arrest.

As we first reported ... Auburn PD, in Washington State, completed its investigation last month, and prosecutors dropped the case -- primarily because the alleged victim refused to testify. Now that the criminal case is closed ... cops are revealing these photos and videos gathered during the investigation.

Evidence - Surveillance - Videos - Accuser - Monique

The evidence includes surveillance videos -- showing Nelly and the accuser, Monique Greene, leaving the Seattle nightclub where they met, getting on his tour bus ... and also the moment when she leaves the bus and calls police to report the alleged rape.

TMZ broke the story ... Greene has filed a lawsuit against Nelly for sexual assault and defamation. Nelly has vowed to sue her, although he's yet to file.

Police - Docs - Nelly - Greene - Versions

The police docs include Nelly and Greene's versions of what went down on the bus, and they're vastly different. Nelly told police their sex --...